High molecular weight polyanhydride and preparation thereof

A high molecular weight polyanhydride synthesized by:

• polymerizing at least one highly pure prepolymer produced from a mixture of anhydrides prepared from at least one highly pure dicarboxylic acid at a temperature and for a reaction time to form a polyanhydride having a weight average molecular weight in excess of 20,000;
• removing the polyanhydride condensation product having a weight average molecular weight in excess of 20,000 formed by said polymerization;
• and
• stopping said polymerization before said polyanhydride condensation product decreases in molecular weight.

A composition comprising a high molecular weight polyanhydride synthesized by:

• polymerizing at least one highly pure prepolymer produced from a mixture of anhydrides prepared from at least one highly pure dicarboxylic acid at a temperature and for a reaction time to form a polymer having a weight average molecular weight in excess of 20,000;
• removing the polyanhydride condensation product having a weight average molecular weight in excess of 20,000 formed by said polymerization;
• and
• stopping said polymerization before said polyanhydride condensation product decreases in molecular weight.

A composition comprising a high molecular weight polyanhydride having a weight average molecular weight of greater than 20,000 and an intrinsic viscosity of greater than 0.3 dl/g in chloroform at 23.degree. C., said polyanhydride produced from at least one dicarboxylic acid selected from the group consisting of:

• aliphatic dicarboxylic acids having the formula:
• HOOC--H.sub.2 C--R--CH.sub.2 --COOH;
• aromatic dicarboxylic acids having the formula:
• ##STR11## aromatic dicarboxylic acids having the formula:
• ##STR12## aliphatic aromatic dicarboxylic acids having the formula:
• ##STR13## aromatic and aliphatic heterocyclic dicarboxylic acids having the formula:
• ##STR14## wherein X is selected from the group consisting of oxygen, nitrogen, and sulfur, and n is an integer between 1 and 3;
• and
• aromatic and aliphatic heterocyclic dicarboxylic acids of the above formula in combination with at least one dicarboxylic acid selected from the group consisting of aliphatic dicarboxylic acids, aromatic-aliphatic dicarboxylic acids, and aromatic dicarboxylic acids having more than one phenyl group,
• wherein R groups are divalent organic radical groups.

A high molecular weight polyanhydride having a weight average molecular weight of greater than 20,000 and an intrinsic viscosity of greater than 0.3 dl/g in chloroform at 23.degree. C., wherein said polyanhydride is produced from at least one dicarboxylic acid selected from the group consisting of sebacic acid, 4,4'-[.alpha.,w-alkanediylbis(oxy)]bis[benzoic acid], isophthalic acid, dodecanedioic acid, 2,2'-[1,4-phenylenebis(oxy)]bisacetic acid, 1,4-bis(carboxymethyl)benzene, 2,2'-[(1-methylethylidene)bis(4,1-phenyleneoxy)]bisacetic acid, 2,2-bis(4-carboxyphenyl)propane;

• terephthalic acid;
• 1,4 phenylene dipropionic acid;
• 4,4'-(n-alkylidene)bis[benzoic acid];
• and cyclohexane dicarboxylic acids.

A method for synthesizing a high molecular weight polyanhydride comprising:

• polymerizing at least one highly pure prepolymer prepared from at least one highly pure dicarboxylic acid at a temperature and for a reaction time to form a polyanhydride having a weight average molecular weight in excess of 20,000;
• removing the polyanhydride condensation product having a weight average molecular weight in excess of 20,000 formed by said polymerization;
• and
• stopping said polymerization before said polyanhydride condensation product decreases in molecular weight.